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CGScreenUpdateMoveCallback

A client-supplied callback function invoked when an area of the display is moved.

Declaration

typealias CGScreenUpdateMoveCallback = (CGScreenUpdateMoveDelta, Int, UnsafePointer<CGRect>, UnsafeMutableRawPointer?) -> Void

Parameters

  • delta:

    The distance, in pixel unites, that the display area has moved.

  • count:

    The number of rectangles in the rectArray parameter.

  • rectArray:

    A list of the rectangles in the moved areas, specified in the global display coordinate space. The origin is the upper-left corner of the main display. The rectangles describe the area prior to the move operation. You should not modify or deallocate memory pointed to by rectArray.

  • userParameter:

    The user data you specify when you register this callback.

Discussion

To register a screen-move callback function, you call the function CGScreenRegisterMoveCallback(_:_:). Quartz invokes your callback function when operations such as window movement or scrolling occur on local displays. When you finish using a callback registration, you should call the function CGScreenUnregisterMoveCallback(_:_:) to remove it.

Note that a single rectangle may occupy multiple displays, either by overlapping the displays or by residing on coincident displays when mirroring is active. You can use the function CGGetDisplaysWithRect(_:_:_:_:) to determine the displays a rectangle occupies.

See Also

Data Types